Search results for "Plate"

Activation of soluble guanylyl cyclase by YC-1 in aortic smooth muscle but not in ventricular myocardium from rat

1997

1 The effects of YC-1 (3-(5′-hydroxymethyl-2′-furyl)-1-benzyl indazole), an activator of soluble guanylyl cyclase, on tension, levels of cyclic GMP and cyclic AMP, and cardiac L-type Ca2+-current (ICa(L)) were investigated in aortic smooth muscle and ventricular heart muscle from rat. 2 YC-1 (0.1–30 μM) induced a concentration-dependent relaxation in aortic rings precontracted with phenylephrine (3 μM). The relaxant effects of YC-1 were reversed by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (30 μM; ODQ), potentiated by zaprinast (10 μM) and antagonized by Rp-8-Br-cGMPS (100 μM). 3 In ventricular heart muscle strips, YC-1 (30 μM) exhibited no effects on force of contraction (Fc) in the abse…

The sGC stimulator riociguat inhibits platelet function in washed platelets but not in whole blood

2015

Background and Purpose Stimulation of soluble guanylyl cyclase (sGC) is a valuable therapeutic strategy for the treatment of several cardiovascular diseases. The sGC stimulator riociguat has been approved for the treatment of two forms of pulmonary hypertension. Platelets contain large amounts of sGC and play a key role in the regulation of haemostasis. Therefore, we investigated the effects of riociguat on platelet function. Experimental Approach The effect of riociguat treatment on human platelet activation and aggregation was investigated. The sGC-specific effects of riociguat were determined by comparing wild-type and platelet-specific sGC-knockout mice. Key Results Riociguat induced cG…

Editorial: Ischemic Stroke Prevention

2014

Optical measurements of an acylated azacrown at the air-water interface

1991

In this study, a cyclame derivative bearing four aliphatic chain substituents shows, like many amphiphiles, solid-condensed as well as liquid-expanded phases. In contrast to the classical amphiphiles, the onset of its phase transition is characterized by a bump-like shape whose amplitude is a function of the compression speed. Ellipsometry which is very sensitive to the monolayer physical state changes, and fluorescence microscopy which has contributed significantly to the understanding of the phenomena occurring in the phase transition region have been used to investigate the monolayer behavior of this compound. This study shows that in the liquid-expanded state, the film is homogeneous an…

Full field automated evaluation of the quarter wave plate retardation by phase stepping technique

2002

Quarter wave plates are optical elements commonly used in photoelasticity to obtain circularly polarized light. They divide the incident light field into two linearly polarized orthogonal components with a phase difference of a quarter of the light wavelength. Due to the tolerance in manufacturing, however, the actual phase shifting produced by the plates is affected by an error, which noticeably influences the photoelastic measurements performed by means of various automated methods. This paper presents a technique, based on the phase stepping method, for the full field automatic evaluation of the quarter wave plate error.

Phase shifting photoelasticity in white light

2007

The availability of image acquisition systems has led to the development of digital photoelasticity both in monochromatic and white light. In particular white light has been used mainly with the following methods: Spectral Content Analysis, RGB photoelasticity and phase shifting photoelasticity. Phase shifting photoelasticity in the colour domain has been used effectively for the determination of the isoclinic parameter in order to reduce the influence of the isochromatic fringes. The method has been also proposed for the determination of the isochromatic fringe order. This paper concerns the general characteristics of phase shifting photoelasticity in the colour domain. Special attention i…

Photoelastic stress pattern analysis using Fourier transform with carrier fringes: influence of quarter-wave plate error

2002

The Fourier transform method, widely applied in photomechanics for the automated analysis of interferometric fringe patterns, has been recently extended to the photoelastic isochromatic fringe patterns analysis. Unfortunately, its use in photoelasticity involves some limitations that have not been completely highlighted in literature. This work deals with the influence of the quarter-wave plate tolerance on the evaluation of the retardation. Both theoretical and experimental analyses have shown that the quarter-wave plate error does not affect the retardation only if the principal stress directions in the model and in the carrier are aligned. In general, instead, the tolerance of the quarte…

Photoelastic Analysis of Edge Residual Stresses in Glass by the Automated Tint Plate Method

2013

The analysis of residual stress in glass is usually carried out by means of photoelastic methods. This article considers the automation of the white light photoelastic method based on the use of a full-wave plate placed behind the glass plate. In particular, the method in based on the use of RGB photoelasticity in white light in conjunction with a full wave plate. The proposed method have been applied to the analysis of membrane residual stresses in tempered glass, showing that it can effectively replace manual methods of photoelastic analysis of residual stresses in glass when a low photoelastic retardation is present.

Visible Photoluminescence of Variable-Length Zinc Oxide Nanorods Embedded in Porous Anodic Alumina Template for Biosensor Applications

2021

Zinc oxide (ZnO) and porous anodic aluminum oxide (PAAO) are technologically important materials, rich with features that are of interest in optical applications, for example, in light-emitting and sensing devices. Here, we present synthesis method of aligned ZnO nanorods (NR) with 40 nm diameter and variable length in 150 to 500 nm range obtained by atomic layer deposition (ALD) of ZnO in pores of continuously variable thickness PAAO. The relative intensity of yellow (1.99 eV), green (2.35 eV), and blue (2.82 eV) photoluminescence (PL) components originating from the different types of defects, varied with non-monotonic dependency on the composite film thickness with a Fabry–Pérot like mod…

The PANDA DIRC Detectors at FAIR

2017

The PANDA detector at the international accelerator Facility for Antiproton and Ion Research in Europe (FAIR) addresses fundamental questions of hadron physics. An excellent hadronic particle identification (PID) will be accomplished by two DIRC (Detection of Internally Reflected Cherenkov light) counters in the target spectrometer. The design for the barrel region covering polar angles between 22 deg. to 140 deg. is based on the successful BABAR DIRC with several key improvements, such as fast photon timing and a compact imaging region. The novel Endcap Disc DIRC will cover the smaller forward angles between 5 deg. (10 deg.) to 22 deg. in the vertical (horizontal) direction. Both DIRC coun…